The present invention relates to speech recognition, and in particular, to speech recognition using historical information.
Speech recognition is the process of receiving speech in a system and analyzing the speech in a recognizer to automatically determine the words or phrases spoke by a user. Speech recognition is useful in many applications. For example, with the growing prevalence of portable devices such as portable phones (e.g., cellular phones), it has become desirable to use speech recognition to control the operation of such devices so that a user does not have to manually enter information into the device. In cell phones, it is desirable to incorporate speech recognition so that users can operate the phone “hands free.” A typical prior art recognition system is illustrated in FIG. 1. At 110, speech input is generated and applied to the input of a recognizer 120. Typically, speech is received by a microphone and converted to an electrical signal using an analog-to-digital converter. The digital representation of the speech signal is the received by recognizer 120. Recognizer 120 then processes the speech signals and produces an output of recognition results at 130. The recognition results may be used to indicate the particular words or phrases spoken by the user as interpreted by the recognizer.
Speech recognition is useful in other applications as well. For example, self service kiosks allow people to access products, services, and information on their own. Traditionally, self service kiosks operate on non-intuitive human interfaces which require some understanding and may limit the types of products, services, and information provided by the kiosk. Speech recognition would make the operation of a kiosk more intuitive and allow for a larger range of products, services, and information to be accessed.
However, speech recognition is rarely a perfect process. Most recognizers can only obtain the correct results a certain percentage of the time. The ability of a recognizer to accurately detect speech signals may depend on a variety of factors, such as the clarity with which the user articulates the speech input signal, background noise, background conversations of other people, or a user's accent to name just a few. Other systemic factors that affect the accuracy of a recognizer include the computing power of the recognizer, the particular speech recognition algorithm or algorithms used by the recognizer, and the accuracy of the conversion from real speech to a digital representation of the speech to name just a few. Because recognizers occasionally produce inaccurate results, users can become very frustrated with speech recognitions systems and may turn the recognition system off or simply opt not to use it.
Thus, it is desirable to make speech recognition systems more user-friendly. Accordingly, there is a need for improved the accuracy of speech recogition. The present invention solves these and other problems by providing speech recognition on a portable device using historical information.